Improvement in machines for bending tubing



2 Sheets--Sheet1.

W. T. FARRE.

Machines for Bending Tubing.

No. 133,636. Patented DEC-3,1872.

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Patented Dec. 3,1872.

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WILLIAM T. FARRE, OF MONTREAL, CANADA.

IMPROVEMENT IN MACHINES FOR BENDlNG TUBING.

Specification forming part of Letters Patent No. 133,636, dated December3, 1872. I

Nature and Objects of the I Mention.

The invention consists of an improved machine, which, by a kind ofpressing, something analogous to the spinning of sheet-metal 1n thelathe, reduces the thickness of a previously cast tube, the said tubehaving been cast with a surplus of metal on the places where the outsideof the curves is desired. When such a casting is cut at the point wherethe curve is intended to be, it shows in cross-section a graduallyincreasing thickness of metal on both sides from the place where theinside of the curve would be, and round to that place where the outsidewould be, the length and the radius of the curve being determined by thelength and the mass in the thickened part of the casting.

Description of Accompanying Drawing.

Figure 1 is a perspective view of the machine. Fig. 2 is a verticalsection through the center of the feed-screw L, ratchet combination K1H, mandrel D, and the partly-formed tube G. Fig. 3 is a ratchetcombination seen from behind, and a section of a part of the frame andthe lifting-bar on the line U. Fig. 4 isa side elevation of the dog,bell-crank lever, lifting-bar, and a section of the frame on the line W.Fig. 5 is a side elevation of axle and dies seen from the fore end ofthe machine. Fig. 6 is the lower die seen from above. Figs. 7 and 8 aresections of castings in the center line. I

General Description.

The machine consists of a frame A, Fig. 1, provided with two uprights,in which the axle O is hung. In the sliding stud Q, at the opposite endof the machine, the feed-screw and mandrel L D is hinged in such amannerthat the head of the feed-screw or mandrel D is resting in the lower dieF. When the casting is put around the mandrel the casting will rest inthe lower die F. The stud Q is made sliding for the purpose of adjustingthe mandrel lengthwise to the desired position in the die F. \Vhen theaxle, with the upper die E, (or dies, as the die-bar has a die at eachend) is moved in the direction of the arrow Z a small part of itsrevolution, from the position shown in Fig. 1, it will stand, with itsstroke nearly finished, directly over the front of the lower die, asseen in Fig. 5.

The device for imparting feed-motion Figs. 3 and 4, consists of a dog,M, provided with two lugs, and fastened on the axle O. This dog actuatesthe bell-crank lever N, which puts the lifting-bar O in motion. On thefeedscrew L the feed-block H fits loosely over the top of the treads.Back of H comes the latch et-Wheel nut K, and between them thepawlcarrier I is fitted, as shown in Fig. 2. The feed-block H isprovided with two studs, which embrace a flange cast on the frame-piece,and also with a wire, 1%, the latter holding the one loop of the rubberspring S, Fig. 3; the other loop of the spring S is lying around thepawl T. This spring S throws the pawl-carrier back when the lifting bar0 falls down, The feed is intermittent, only feeding when the dies arenot working. serves to limit the descent of bar 0, and thus to regulatethe degree of feed. The working faces of the upper dies are slanted orbeveled slightly so that no scraping action can take place; but thefaces will work on the lead or other metal in the manner of a burnisher;consequently they ought to be well hardened and polished. The lower dieconimences its work from the line on either side of the tube, where theupper dies stop working, and works from there downward on either side ofthe tube for about sixty degrees; the remaining sixty degrees, more orless, in the bottom of the die needs no working, and the working-rim onthe lower die is, in this place, hollowed slightly down to prevent itfrom Working. The working-rim in the lower die consists in a convex rimlying inside in the front end of the die. This rim is running all alongthe front lip of the die, and is convex in its cross-section. It is notseparate from the die, but formed in the metal of the i die. It ismarked a on Fig. 6. This rim is, of course, the die proper, and is ofthe size of the tube desired. The tube casting,- which 15 P, theadjusting-screw,-

something larger in the thickened part, cannot consequently come downuntil the upper die forces it down, and in doing this both dies act uponand displace the eccentric portions of the tube, reducing it thus to atube with walls of equal thickness; but as there was more metal tostretch out on the upper part of the tube than on the sides and nothingat all underneath, the tube will form a curve downward, said curve beingproportionate to the excess of the mass of surplus metal in the casting.

To work the machine, insert a casting from" the front end of the machinearound. the mandrel D, until its inner end enters into its serrated seatin the feed-block H. Get the thickest of the thickened part above, oilthe casting, put the machine in motion either by a belt, a coupling, ora crank, in the direction of the arrow, Fig. 1, and let it work untilthe curve is formed. When there is another curve to form, as in astench-trap, withdraw the half Claims.

I claim as my invention- 1. The combination,with the dieFand mandrel D,of the revolving plate-die E, the construction and combination of theparts, and the mode of operation of the combination,being substantiallyas specified.

2. The combination, with the threaded mandrel stem L and thelifting-bar, O of the intermediate mechanism through which feedmovementis imparted to the tube, substantially as described.

W. T. FARRE. \Vitnesses:

WILLIAM H. BARWICK, NEOOLAI HATS.

